A Devil Inside
by TibiIpsiDicVere
Summary: Post-Clockwork Prince, starring Will, Jem, Tessa and Cecily...


Will twisted the handle of the door and walked in. He had no notion of what he was about to see.

Jem and Tessa, folded close to each other, pressed against the edge of a wooden table. Will felt the lacerating beat of his pulse as he helplessly watched their lips mould around one another's. Tessa's lips – the touch, shape, colour of them so scored in his memory he could nearly _feel _them on his – slipped in between Jem's. Will could only stand, paralysed into gawping immobility, as their kiss deepened. Tessa moaned erotically from her throat, to which Jem responded by pushing his body closer to her's.

Tessa leaned backwards, and her left leg began to rise around Jem's. Jem's eyes darted over to Will's and – abruptly and awkwardly – he severed himself from Tessa. Tessa's mortified gasp when her eyes alighted on their spectator, and her laboured breathing, shattered the cold tension of the drawing room.

Will could not help it, and yet he knew that when his gaze wound with her's, he would experience the horrid, grinding feeling in his chest; and he did. Her eyes were wide - the colour in her cheeks hyper and scarlet as a slit vein pouring blood. She looked away quickly, hanging her head in shame.

Will shifted his gaze to Jem. Although Jem also looked sheepish, it was plain he was not so humiliated as his fiancée. His mouth was parted slightly, as if he was about to explain himself. And Will _wanted _him to. Will chastised himself – he had no right to that; Jem did not answer to him. And he had no right to feel so hideously jealous, either; Tessa was not and never would be, his.

That thought was no longer creeping, and it had long since ceased to cause him any pain. Will had thought it, revisited it, slept in it and cocooned himself in it so much since that dreadful day he was inured to its power. But that was the problem – it failed to blot out his infernal imagination; the insidious, snaking fantasies had already germinated before his conscience had time to whip them back into submission.

Just now, for a flashing, lightning second, Will had wanted to tear Jem from Tessa. He had imagined himself striding over there and—

_No._ Will reigned in the violence roaring inside him to be liberated. He couldn't think it. He…had wanted to hurt Jem. Yes, that would suffice. 'Hurt' didn't necessarily mean what he had imagined.

Still, it seemed half-mad, the thought that he would ever intentionally hurt his brother, his parabatai, who he would willing die for. Barbarian, monstrous. _How could I ever think such a thing? _

"Will, I'm sorry—" Jem began.

"It's fine." Will had not planned to cut off Jem's apology; but he had. He had planned to make some witty remark; but he hadn't Suddenly, he didn't know what to say. He had forgotten why he had even chosen to come in here in the first place. His eyes scudded over to Tessa's, who had regained some composure, but her breast was still heaving and she was blinking fast, as if she couldn't bear to look at him.

As he looked away, he remembered. "Charlotte thought you might want to know that Woolsey Scott is here to give us more information on Mortmain's platform in Downworld among the werewolves."

Will heard the beginning of Jem's reply, but it was muffled by the sound of Will shutting the door behind him.

Will did not care for Woolsey Scott. He did not care for anything at all. Charlotte was qualified enough to deal with him alone.

Will found himself wandering, and then sitting in the training room. He could not remember, exactly, how he came to be there. He was idly twirling a seraph blade in his left hand. Will's eyes were riveted to the shots of white light that splintered off the runed metal as it touched the bright light springing through the window.

Will's mind was not on what he was doing — his mind was displaced; absent. Will felt strange, as if he was _still_ watching the spectacle he had just fled from. Will knew that his mind would not cease torturing him with revisions and re-imaginations of it all day — it would not be in the interest of his sanity to sleep tonight. Will no longer possessed the strength to endure his dreams; more of them could only result in physical sickness, which he had to avoid for Jem's sake.

Will heard the training door open. He looked up dazedly.

Will felt terribly drunk as he forced out the words, "Well, what are you standing there for, Cece? You almost look shy."

She stepped in and shut the door behind her. "And you look mighty miserable. What's wrong now?"

"What do you want, Cecily?" Will enquired tiredly.

"I was exploring. The Institute is an enormous place, yet I fear a rather dull one for fifteen year old girls."

Will said nothing in return. _What does she want me to do about it? _Will thought.

"You're awfully taciturn, Will. When we were younger, we couldn't stop your mouth going for a kingdom."

"And _you_ haven't changed a bit — still just as cheeky now as you were then." Will flipped the blade into his right hand, whirling it around.

Cecily's sapphire blue eyes, almost a mirror image of his own, but not quite, locked on the blade. "Oh, so you _do_ remember me then, William? There was me thinking you'd forgotten you _had_ a family."

Will turned his vitriolic gaze on her. "What. Do you _want,_ Cecily?"

Cecily lifted her chin. "I want you to train me."

"What? No!" Will's response was automatic; he did not think about it.

"What? Why not?"

Will did not know why not but he knew there was a reason – a good reason – but it would not surface from the gloominess of his mind.

Cecily continued, "As a Shadowhunter, I am _entitled _to be trained. You can't stop me."

"Yes, I can – I'll simply refuse to train you."

"You can't do that."

"You know I can." Will argued.

"You can't. I'll tell Charlotte. It's _completely _unfair—"

"Oh, by the angel, don't tell me Charlotte has become mother's replacement for telling me off—"

"But the servant girl—Sophie — she was trained! And so was Tessa! And they don't have so much as a drop of Angel blood in them!"

"That's not strictly true—"

"Will! Please!"

"Na!" Will stabbed the blade ferociously into the wooden floor. It wobbled as he stood up. "Now, for god's sake, go and report me to Charlotte and leave me alone."

Cecily is silent for a second, her gaze fiery. "If this is about what happened to Ella—"

"It's not!" As he said it, Will was suddenly unsure that it _wasn't. _He remembered Ella saving him, a lifetime ago it seemed, from the demon, and then Ella's body stretched out on the bed, dead—He could never let that happen to Cecily-

"Really? Who, then? Your precious Tessa?"

Will was too stunned to say anything. He wanted to speak, to refute what she suggested, but his voice would not be commanded. Cecily chuckled humourlessly. She shook her head at him. "I knew it."

"Knew what?" Will asked.

"I knew it was because of her that you were behaving like this."

"Like what?" Will heard his tone sour.

"Need I spell it out?! I've seen the way you look at her. I know that look. It's the way father looks at mother…You love her, don't you? _Don't _you?"

Will said nothing. Apparently, he did not need to; Cecily looked convinced of it merely by his expression without any verbal assent on Will's behalf. "And she's engaged to another. Your _parabatai, _no less."

Will's throat ached horribly. Wide grey eyes hovered, ghostly and frightened, in front of him. He smelled her everlasting perfume of lavender, felt it becloud him. He felt as he had when he had taken a dose of Yin Fen; wild, exhilarated; disorientated and numbed—

And he saw it again – Jem and Tessa. In the drawing room. Against the table. Except now Jem was kissing down her throat, his hands roaming over her chest. Will saw flashes of his tongue against her skin. Tessa's hands curled in Jem's hair and she gasped again and again. Jem's hands moved to the edges of her dress, and he wrenched the material apart, revealing her naked flesh—

And then Jem disappeared. Will was thrown into the past. Tessa was standing by the fireplace, and he was sitting in a chair, his head in his hands. The words Tessa had just spoken repeated over in his head _"I love him, I love him, I love him…" _like a savage dog's teeth relentlessly ripping into a gored and maimed limb; again and again and again.

But it was just him, and Cecily, in the training room. That was all. Will realised he was on the brink of tears._ By the angel. In front of my little sister. _Will sank down onto the wooden stair again, thrusting his hands into tangled curls of his black hair, covering his eyes. He felt moisture slide over his palms soon enough. Cecily's voice appeared, gentle yet firm. "Will, just because you're wretched about her does not mean you have the right to punish everyone else for your pain. Forget about her. Mourning over her won't make her love you. And I _will _be trained, William. You're not going to stop me."

Will wanted to scream, _How?! How can I possibly forget about her?! _And with that, Will heard the stomping _clack _of her shoes over the wooden floorboards – and the harsh bang of the door.


End file.
